Abstract:
Solid waste generation is increasing day by day globally. Similarly, in Pakistan
more than 50% of the municipal solid waste is biodegradable and contributes to
greenhouse gas (GHG) emissions if not managed properly. To address this issue
there’s a need to use a waste management technique that is economically feasible,
environmentally friendly, and practically possible. Composting of organic fraction
of municipal solid waste is one of the promising techniques for converting waste
into a resource. This study was aimed to convert waste (organic fraction of
municipal solid waste) into a resource (compost) using three different bulking
agents (wood shavings, dry leaves, and corn stalks) in three different reactors. The
composting mixture was monitored for its characteristics like temperature, moisture
content, TS, VS, TOC, TKN, C/N ratio, TP, and pH. Secondly, the GHG emission
potential of compost was determined at different stages of compost formation. The
final compost using three different bulking agents had C/N ratio of 20.6, 15 and
12.4 for wood shavings, dry leaves, and corn stalks respectively that is considered
an ideal value for mature and stable compost. The results of GHG emission potential
showed that raw waste had maximum GHG potential of 3114, 2926 and 2833 g
CO2eq/kg compost for wood shavings, dry leaves and corn stalks respectively as
compared to final compost having GHG emission potential of 934, 832 and 736 g
CO2eq/kg compost for wood shavings, dry leaves and corn stalks respectively.
Moreover, the net GHG emissions were found to be minimum and almost similar
for all the three bulking agents in the final compost. Together, the results showed
that composting of waste with bulking agents can produce a stable compost and can
significantly reduce the GHG emissions.
